PCB and the importance of their proper Protective Finish

Without doubt the Printed Circuit Board is one of the most important components in each electronic device. The PCB is the base for all other electronic components and interconnects them electrically via copper circuit foils. The parts of these foils which are soldered to the components are called soldering pads.

These pads determine the quality of the electrical connectivity of the PCBA, that results when component terminals are soldered together with the pads. Morever, it is important to cover the pads with a finish; a protective, conductive layer. Mainly also to protect the copper, an element which can rust easily.

The correct protective finish depends on the PCB, the types of components and the manufacturing process. There are different finishes depending on the usage of the final electronic device and manufacturing method. Each finish has its pro and cons. Basically it is essential to choose the proper protective finish in order to achieve the highest quality assembled device. As en example, HASL lead free (hot air solder leveling) is robust and very weldable, but it has little flatness and is not appropriate for components such as BGA. Immersion tin finish is very flat but cannot withstand as many thermal soldering processes as the HASL or ENIG (Electroless nickel immersion gold), in case when doing double reflow. However, ENIG is more fragile and unsuitable for the press-fit process.

Nonetheless, the proper protective finish in only one key point for high quality PCB manufacturing. Besides being experts with the manufacturing and assembly process, electronic components and testing, Actsource always takes into account all other other factors of the manufacturing process, such as delivery timescale, storage periods, minimum order quantities for all electronic components that must be purchased.

For more information please contact Act Source Ltd., email: This email address is being protected from spambots. You need JavaScript enabled to view it.